Chosen Solution
My mac pro has started going completely black at random times and while black I cannot even see the logo from rebooting etc. It is mostly black now but comes back on for a few seconds and is fully functioning then. The black screen is the black of an off computer, not the backlit black. External devices like the backup drive and charging cable are working perfectly. While connected to the external display via HDMI and adapter I can use the keyboard and trackpad (looking at ext display) just fine. Both occassionally go gray as it switches displays, but when the mac is fully blacked out the ext display is fine. Also, I don’t know if this is normal or not, but I can close the mac while the screen is black and the ext display is unaffected. Things I’ve done: Turned off screen timeout in power options and battery optionsBacked up successfully using an external display to see progressReset the SMCReset the PRAMDownloaded the Big Sur OS update, but mac is still running Catalina
With the screen black what happens when you shine a flashlight though the lids Apple Logo (a poor mans backlight) do you see the faint image of your desktop and its icons? If you do your screens backlight needs repairs it could be a bad display cable or the logic board connector. Upgrading the OS to Big Sur won’t alter things here I would hold off doing that. Update (01/27/2021) At this point this is starting to sound like a damaged T-CON board which is located within the lid with the LCD panel. What can happen is screen cleaner can drip down into it corroding it and/or the display data cable connector. Here’s a teardown of the display so you can see where things are MacBook Pro Retina Display Teardown Here’s a deeper view of the T-CON board its self, it’s not replaceable on its own!
Here’s the needed part: 15” MacBook Pro Complete Display, Apple P/N 661-02532 Don’t wait to long! As these displays go fast. Keep in mind the part is no longer being made this is a recycled display from a very good supplier.
